Steam for Linux

When I browse this forum from Firefox, no problem.When I browse this forum from the Linux Steam client, I have a problem.

Anytime I mouseover a thread title, a tooltip pops up that gives the first few lines of the thread. However, anytime this happens, the Linux Steam client momentarily freezes. I can't scroll, move the window, click on anyting else, get it to respond in any other way.After a few moments, the tooltip disappears, everything becomes responsive, and usually it goes through all the previous actions I did with it.